The factual Antecedents This is a petition for mandamus filed by petitioners to compel the Office of the Executive Secretary and the Department of Foreign Affairs to transmit the signed copy of the Rome Statute of the International Criminal Court to the Senate of the Philippines for its concurrence in accordance with Section 21, Article VII of the 1987 Constitution. The Rome Statute established the International Criminal Court which "shall have the power to exercise its jurisdiction over persons for the most serious crimes of international concern xxx and shall be complementary to the national criminal jurisdictions."1 Its jurisdiction covers the crime of genocide, crimes against humanity, war crimes and the crime of aggression as defined in the Statute.2 The Statute was opened for signature by all states in Rome on July 17, 1998 and had remained open for signature until December 31, 2000 at the United Nations Headquarters in New York. The Philippines signed the Statute on December 28, 2000 through Charge d’ Affairs Enrique A. Manalo of the Philippine Mission to the United Nations.3 Its provisions, however, require that it be subject to ratification, acceptance or approval of the signatory states.4 Petitioners filed the instant petition to compel the respondents — the Office of the Executive Secretary and the Department of Foreign Affairs — to transmit the signed text of the treaty to the Senate of the Philippines for ratification. It is the theory of the petitioners that ratification of a treaty, under both domestic law and international law, is a function of the Senate. Hence, it is the duty of the executive department to transmit the signed copy of the Rome Statute to the Senate to allow it to exercise its discretion with respect to ratification of treaties. Moreover, petitioners submit that the Philippines has a ministerial duty to ratify the Rome Statute under treaty law and customary international law. Petitioners invoke the Vienna Convention on the Law of Treaties enjoining the states to refrain from acts which would defeat the object and purpose of a treaty when they have signed the treaty prior to ratification unless they have made their intention clear not to become parties to the treaty.5 The Office of the Solicitor General, commenting for the respondents, questioned the standing of the petitioners to file the instant suit. It also contended that the petition at bar violates the rule on hierarchy of courts. On the substantive issue raised by petitioners, respondents argue that the executive department has no duty to transmit the Rome Statute to the Senate for concurrence.